Rough sketches are different than crudely-drawn diagrams. In fact,
many rough sketches are very well drawn: http://tinyurl.com/2a27ed
I¹ve been doing concept sketches for a lot of years, and the majority of
these examples are not rough sketches, no matter what the authors or Google
call them. The first example on Jared¹s site ( of the space station ) is
more like it.
Just watched a movie of a tool called SketchUp. Maybe I've been asleep, but
I hadn't heard of it before. I post it here because it looked to me like
they have achieved some nice, natural direct-manipulation in 3D.